Method of making ingots.



L. W. SOUTHGATE. METHOD OF MAKING INGOTS. APPLICATION FILED MAY 21,1909.

Patented J an. 6, 19:14.

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METHOD or MAKING I mo'rs.

Specification of Letters Patent.

. Application fled ra 21,1900. Serial in. 49 7353.

To all whom it may concern: 1

Be it known that I, LoUIs W. sournoa'rn, a citizen of the l 7 Worcester, in the county of Worcester and State of Massachusetts, have invented a new and useful Method of Making Ingots, of which the following is a specification.

- In (gasting ingots, articularly the ingots used in the steel in ustry, difliculty is eneounteredin obtaining a cast free from ini. perfections 'and'cavities. The cast solidifies the cast solidify or freeze, the oeli'ter remains United States, residing at liquid or semi liquid and as shrinkageoccursa cavity called a pipe forms at the top central part of the east which pipe extends down intothe' cast some considerable dis-' tance. These cavities or pipes usually will not weld or heal as the ingot is rolled. The. Y crust whichforms on the top. of the cast is liable to prevent the escape of occluded gases and for thisreason'blovs holes or-cavities are apt to form in the upper part ofthe cast. The dificulties are so serious that itis the present practice in steel mills to crop thei ingot, that is, to roll same down partially 5 and then cut off a section thereof corres sponding to the upper end of the cast. This cropped end has to be remelted and thus- *the heat and work connected therewith is lost. But more serious than-this loss, is the liability that-the imperfections may extend down below the part of the ingot which is cropped off and discarded. Thus for examvple,-in a rail mill if twenty per cent. of the. ingot is out ofl, there is no surety that all the flaws are eliminated, and if all the flaws are i not eliminated the rail will be defective near railroads insisti its end. vFor this reason there is a great deal of controversy between steel mills and railroads about the amount of cropping, the on the cropping of a large section of t e ingot which the steelmills hesitate about on account of the loss.

Various methods have been suggested for preventing piping but so far as I am aware no satisfactory solution of the problem of I making a better cast has been reached. One

solidifies. This method'is very expensive asthe molds M 'used for casting ingots 1n a proposed method is to apply heavy pressure as by hydraulic machinery to the cast as it it involves heavy molds, hydraulic apparatus and appliances, and retards reduction. The method so-far as I am in ormed has never come into use except in special in-- stances where the necessity of making a bet-- ter more than balances the great cost. Another method'that-has been proposed is to keep the top of the ingot molten for a long time'so that the tendency to crust over the top will be retarded and so that. the

molten metal at thetop can settle down and fill'the pipe as the same forms. This'method has been-practised by applying a gas flame PatentedJan1h 1914 on top of the ingot .to prevent the same solidifymg. This 1s expensive and is apt to spoil the top of the mold. Another way of carrying outithi-s method is by protecting the 5 top of the mold byheat insulators but so far as 1 am informed this has not proved very satisfactory. Another way of carrying out this method is by arranging a' series of molds so'that one will pour or drain into the next whereby molten metal will be supplied fora considerable time to the tops of the molds. ThlS method is uncertain, requires special molds, and only acts to improve part of a' seriesjof casts. I have discovered that the methodof mak-' ing a cast by keeping the top part thereof molten for a long time can be carried out by agitating or stirring the molten metal at the top of the cast while the body of the metal solidifies. This will prevent the formation of a; top crust and will keep the metal. at the top molten for a long time so that the same an act to fill the pipe by gravity. This improved method. may bepractised very economically in connection' wi-th the apparatus usedin any ordinary steel or rail mill.

In the accompanying drawing: -Figure 1;.

is a seetion al view illustrating an ordinarycastor ingot C with 'a pipe P and blow holes B-B. Fig, 2 is a similar view illustratin'g how a body of molten metal L at the top acts to fillup any tendency to pipe and to prevent any crusting over of the top to retain the occluded gases in the cast.=' Fig. 3 is a similar-view illustrating how a stirrer or agitator may be employed to-" keep met-adition in accordance with my invention.

I the at the top of the mold in molten con- Fig. 4 is a similarview of 'a cast made by .my' improved method. Fig. 5 is a diagrammatic view illustrating one form of .mecha- .nism for practisinfgmyinvention, and Fig,

6 is anend view 9 he stirrer or agitator.

1 have shown my method as applied -.to I Y rail mill. Two of these molds are usually mounted on a car N, which molds :are run vention as expre: sed in .the claims made in the form of a rake. This rake consists of a bar 10, cross bar 11, and downwardly extending rods or teeth 12. 1 Cylinders of fire clay are arranged on the bars 10 and 11 and teeth 12 to prevent burning or melting ofthe same. The rod 10 is pivoted at one end to a lever 14, loosely mounted on avpivot or shaft 15. Passing through the lever 14 is a rod. 16 having nuts l7-17 threaded 'onits ends. Springs 18 are arranged ibetweenthe lever l4,- and nuts 17. The rod 16 is connected to a yoke.19 which has rollers engaging cam- 20 on shaft 21. By this mechanism if the-shaft 21 is ro-' tated the lever 14 will be rocked or vibrated. It also will be noticed that an adjustable spring relief is afforded by means of'the springs 18.18 whereby if the stirrer sticks breakage" will not occur. The other end of the rod is supported by a rope 22 passing over an over head pulley 23. The other end of the rope is provided with a ring 24 which may engage hooks 25 or 26. A number of these mechanisms may be arranged in line on shaft 15 and may bedriven from shaft 21, if it is desired to practice the method with a plurality of molds such as the ordinary train of cars carrying molds filled from a charge of the pouring ladle.

The method is practised as follows: After the mold is poured the car carrying the same is run to a position opposite the stirrer S. The stirrer is then lowered into the mold M by the rope 22 and is left to reciprocate with its teeth projecting into the molten metal as long as desired. This will keep the metal in the strata operated upon by the stirrer in .an agitated condition, and 'will prevent any crusting or solidifying over the top of the cast. The occluded gases can escape so long as the stirring operation con-. tinues. While this stirring operation is takingplace the ingot is solidifying below said strata from the outside toward the center, and from the bottom toward the top. The strata of metal 0"perated upon by the stirrer being kept in an agitated condition and being prevented from solidifying, at the end of the operation,- there will remain a layer of molten metal at the top, and a partially solidified ingot below, Land this moltenstrata will act to correct any tend-- ency to pipe as the ingot completely solidifies thereafter. Thus thecharacter of the cast can be improved and the method adds very little, if. anything, to the cost. The ingot made b this method will be much improved in c aracter andcropping can be reduced or possibly eliminated.

Manyother forms of apparatus may bev worked out for practising the invention without departing from the scope of the in- Having thus fully described my invention what I claim and desire to secure by'Letters Patent is 1. The method of preventing piping in ingots which consists in stirring the'molten metal at the top. of the cast to keep the same molten while the body of. the cast sets or solidifies. v I

2. The method of making ingots which consists in filling a mold with molten metal and agitating or stirring the metal at the top of the mold while the metal below remains unagitated so that the metal at the top of the mold will be kept in liquid form to fill the pipe or shrinkage cavity.

3. The method of making ingots, which consists in filling a mold with molten metal,

and agitating or stirring the metal laterally at the top of the mold to keep thesame molten while the body of the cast sets or solidifies.

4. The method of making ingots which consists in pouring molten metal into a mold and agitating or stirring the top strata of the metal laterally to keep the same molten while the body of the cast below sets or solidifies.

5. The combination of a mold, of a stirrer which can be inserted in the top of the same, and means for reciprocating the'stirrer sidewise of the mold.

6. The combination of a mold, of a pivoted stirrer which can be inserted in the top of the same, and means for reciprocating the stirrer sidewise of the mold.

7. The combination of a mold, a stirrer made in the form of a rake having. its teeth protected with fire clay, and means for moving the rake. I I V 8. The combination of a mold, an agitator for stirring the metal at the top of the mold comprising a rake pivoted to a lever mounted on a-shaft, and means for oscillating the lever. Y

9: The combination of a mold,'means for agitating themetal at the top of the mold consistin of'a rake, a leveriloosely mounted on a sha 't to which lever" said rake is connected, and means for vibrating said lever, said means having a spring relief.

10. The combination of a mold, and means mold, consisting of a rake,'-a cord or rope for supportin one end of the rake so that the same can e lowered into the mold, and

'means for reciprocating the rake.

; .In testimony whereof I have hereunto set my hand, in the presence of two subscribing witnesses. 

